1. Field of the Invention
The present invention relates to a golf club head in which a spring effect and a productivity of a clubface can be improved in a well-balanced manner.
2. Description of the Related Art
Recent years, it has been proposed a hollow golf club head with a face portion which has an inner surface being provided grooves thereon in order to improve a spring effect of the face portion. Since such a golf club head has a small rigidity and flexibility of the face portion, a large flexure of the face portion when hitting a ball can be produced.
For example, as shown in FIG. 9, JP2002-253709A1 proposes a golf club head (a) which has a face portion (b) with an inner surface (ba) being provided circular grooves c1. Since the face portion (b) of the golf club head (a) has flexibility, it has an improved spring effect. However, each circular groove c1 provided on the inner surface (ba) of the face portion (b) described above comprises a plurality of arcs with the different radius of curvatures. Therefore, it is difficult to process these circular grooves on the inner surface of the face portion.
It is an object of the present invention to provide a golf club head in which a spring effect and a productivity of a clubface can be improved in a well-balanced manner.